Automatic shut-off mechanism



Sept. 13, 1932. E. w. MEARS AUTOMATIC SHUT-OFF macrmm gm Fi led July 3, 1931 Patented Sept. 13, 1932 1;, ii TATQES i P TENT 1 caring EDWARD w. HEARS, or wanton, rENNsYLvANIA,Ass1eNon rroMEAa's-KANE-ornma', Ind, or rHInAn LrNiA, PENNSYLVANIA;

A CORPORATION 015 PENNSYLVANIA AUTOMATIC SHUT-OFF MECHANISM A Application filed July 3, 1931. Serial No. 548,501.

, The present invention may be considered to some extent a development ofmechanism forming the subject matter-of U. S. Patent No. 1,288,1 19 entitled Automatic low water fuel shut-off and relates to shut-ofi' mechanism.-

While intended to be appliedito any purpose to which it may be adapted it'is believed the invention will have its best and widest application for the automatic shut-off of a fuel line to a boiler responsive to undesirably low water in the boiler, with or without an adaptationto effect the shut-off, also by thermostatic orother means, as in the event of any momentary stoppage in the fuel supply to the line. 1 v

One-purpose of the invention is to provide mechanism of the character indicated, easy and inexpensive to manufacture and well suited'to the needs of service.

Afurther purpose is tofshie ld the p acking land and stem of an automatic emergency 2:) I shut-off valve from moistureand dust, thereby protecting the valvefrom danger ofit sticking open in release, even though the automatic release to effect valve closuregmay i come only between indefinitely long intervals.

- 'mountedat-its outer end'upon the outerend A further purpose is to surround the outer portions of the packing gland and stem ofan automatic emergency external annular inwardly directed hood,

of the valve stem, forming a portion of the valve unit and preferably coaxial withthe valve stem; r r

i A further purpose is to provide a bell crank;

release latch'pivoted near the outer end of an inwardly pressing'valve unit with a release arm making engagement with an automatic release member in the extended axis of the valve stem.

T A further purpose is to provide'anovel bonnet assembly adapted to use with standmaking the asard commercial valve bodies, sembly interchangeable with. the usual bonnet of the commercial valve for the easy conversion of an ordinary screw closure valve iinto an automatic release to closure type .of

. valve, adapted to be latched normally open,

and to close automatically under emergency tion in the (position of shut-off valve with an condition making the emergency. A further purpose is to avoid need for accommodation between the angular positions of the valve bonnet and of a release member by effecting the release in: the extended axis of the valve unit, permitting angular variathe bonnetto-jbest accommodateother conditions, that may be with respect to the requirements of another automatic release element having an effective engagement at a point offset from the stem axis or be merely to permit the bonnet tobe screwed home without need for any definite angular registry with respect to the'first release member.

A further purpose is to mount a bell crank upon a bracket portion of a valve bonnet in a way adapting a lateral projection upon a downward arm of the bell crank, to latch under a downwardly directed hood surrounding the outer portion of thepacking gland and; carried by the outer .end of the valve stem and to provide anupward extens on from a horizontal arm of the bell crank to lie substantially coaxialvwith the stem, to receive and guide a release element equally well at variant angular positions of the bonnet.

Further purposes will appear in the specification and in the claims.

I have elected to how one form onlyyof,

myinvention, selectinga form that is prac tical andefiicient illustrates the principles involved.

Figure 1 is, a side elevationvof mechanism embodying a desirable form of my invention,

and illustrates anautomatic cut-off valve in a fuel line to a boiler or the like, with the valve unit latched open and operatively connected to release mechanisms.

Figure 2 is a viewcorresponding. to a portion of Figure 1 in longitudinal. sectionin the plane of; the paper andwith partsin a different position, the valve unit being latched openin Figure 1 and closed in Figure2. I

-Like numerals refer to like parts in all figures, :1

in operation and which well Describing in illustration and not in limitation and referring to the drawing In the illustration, an automatic shut-01f valve 3 in a fuel supply line 4 of the boiler 5 has a valve unit 6 latched open by a projection 7 on a bell crankrocker 8, and is sub- Ject to an emergency release for automatic closure by an emergency downward -move ment of a member 9 or by an emergency lateral movementfin the direction of the arrow) of a member 10. w

The members 9 and lO 'are intended to be connected in any suitable way, to move responsively to any selected di'fl erent emer gency conditions under which it is undesirable tor the'valveto remain open.

7 valve.

More usually these conditionsf under which there is to be a safety shut-oil? of the valve include any dan erously low water in the bdiler or any ina vertent failure of the fuel V supply '-to the pipe 4.

T e member 9 while optionally comprising any member adapted to move responsively to selectively variant emergency conditions has been shown in the illustration to operate by mechanism responsive to dangerously low wateriinthe boilerpin that some features of the invent on are in advantageous combination with this specific type of latch-releasing comprising'the unchanged standard body of acommercial Valve with the bonnet assembly mounted thereon interchangeably with the usual bonnet assembly of a standard The'bonnet assembly includes the bonnet, connected in any usual or suitable way to the 'body,'a valve unityalatch and springs 'for respectively retracting the valve unit in wardly to closure and for holdin'g'the latch to its duty.

p The bonnet comprises a usual base" 12 and valve stem housing'13 that may bethe same as the; corresponding members of a usual bonnet, and .a bracket 14 laterally spaced from andisuitably parallel to the housing-13,

the bracket supporting the-'latch'mechanism.

The coaxial'base and housing :are 'bored longitudinally forthe valve stem' and coun- -terb0red at the inner and outer ends of the bore to respectively'receive the compressed spring15 that downwardly retracts the valve unit and packing washers 16 held to a suitable screw. gland cap 17.

The valve unit 6 comprises a stem'18, slid-' able in the bore of the housing with aya'lve place by 19 at its inner end and an inwardly directed hood 20 at its outer end. i i

The inwardly directed hood 20, rigidly and preferably coaxially fastened at its outer end to the outer end of the stem is suitably a casting. Its annular wall surrounds and shields the outer end of the stem "and the opening to the packing around the stem from dust, and drippage, andits inwardly directed'end provides an abutment for engagement by the latch member 7 on the bell crank 8.

The annular nature of this abutment permits a free angular movement of the valve unit on its own axis without afiecting the proper operation of the latching mechanism. The'bell crank 8 pivoted at2l on the outer end of the bracket has a downward arm carrying the latch projection 7 ,and-a lateral arm for engaging the release member 9 in the extended axis of the valve unit, the lateral arm carrying a bayonet 22 that extends approximately :axially of the valve unit and provides a loose guiding connection with the release member 9. I I

The latch projection 7 is illustra'ted as the head of a screw though obviously this projection and other portions of the bell crank maybe integral portions of a singleca'sting.

The downward arm of thebell crank 8:.

desirably extends suitably beyond the projection 7 to provide anengagement' surface for the laterally operating'release member 10.

The latch member is spring pressed to its 7 duty by asuitablespring 23 carried on thef bracket. Though other means may be used than the spring for efi'ectingthisresilient urge in counterclockwise'(Fi'gures 1 and '2) direction, we have found the spring a little superiorto any other means able'float chamber 25 is carried at the end of an'arm 26 rigidly fastened toa shaft 27 that is j ournalled inthewall of the chambers.

and extends outside the chamberto carry rigidly connected to it an arm' 28 that 'in turn carries'the downwardly extending sleeve link 9.

. It will be seen that the vertical-position of the'lmk 9 depends upon'thewater level within=thechamber25 and' therefore upon that within a boiler -5 to which .the chamber'is connected at 29 and 30 respectively aboveand below'the waterlevel of' the boiler.

I v tried inthat-it is lessefi'ected'by floor vibrations. Inthe illustration afloat 24 within a suit-.

In the event of abnormally lowwaterin the boiler the abnormallylow position of the float brings the link 9' into operative engagement with'therocker 8 to release-the valve unit "for automatic valve closure.

The release member 10 may beresponsive to a thermostat and e'fi'ect latch release and "valve closure irrespective ofthe condition or the water in the boiler if the gas: supply 1 in the-"fuelline shouldiail.

raver-9 A particularly desirable feature of the in- 1 vention is the locating of the operating porf tion of the lateral arm of the bell crank 8 in the extended axis of the valve unit which permits the angular position of the bonnet assembly to be varied to best accommodate other conditions either with respect to the location of any other release member 10 operating at a portion of the latch that is laterf latching with the'unit and a release arm be- {yorid engaged'and inwardly 'deflectedl at the extended ally offset from the axis or merely to avoid any need for definite angular registry of the bonnet assembly when fastened to the valve.

Desirably the changeable with mercial valves, the body portion 11 of the valve varying in any usual or suitable way, usually without involving need for any change whatever in the bonnet assembly.

It will be understood that the automatic shut-off valve 3 is usually an emergency safety I I device and during normal use there may be very long periods during which the device is on duty but forgotten.

This makes it very desirable that when the emergency finally does come there may be no danger of the valve unit sticking open after release and danger incident to moisture and dirt settling into the connection between the. stem and gland.

When used as illustrated there has been frequently drippage from the float chamber,

water seeping outwardly along the shaft 27 i to eventually drip from the operating link 9 i on to the release valve.

In the pastthis drippage and dust has so worked in along the stem of the valve as to result in a deleterious sticking wholly avoid ed by the hood 20 of the present invention, any such'dripping as well as settling dust being effectively shielded by the hood from the valve stem.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such in so far as they fall within the reasonable spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In automatic valve shut-off mechanism including a valve unit having an axis and resiliently pressed longitudinally inwardly when latched from inward movement at an outward open valve position, a latch, a movable lever carried by the latch and having an arm extending into line with the extended valve assembly is made interbonnets of standard comhaving a pivot support in the past there has been this member at the isaid'axis andmeans for sup- P g ever to permit and control the characterof'movement' of the lever;

2. In automatic v Shut-0E mechanisllt including a: valve unit having an axis and "resiliently presse d longitudinally inwardly when-latched from inward movement at'a'n "out-ward open valve position, a bell crank latch release-pivoted near the outer end of 1 apointlaterally ofi'set therefrom and flhajvi'ng fan" inwardly extending: arm

the outer end "o'fthe unit adapted to be axis of'the unit-torelease the latch.

3. In mechanismbf thechar'acter indicated, a bonnet having a longitudinally bored body, carriedon'theinner end of the stem and an inwardly" directedannular hood upon the outeren'd of the stem substantially coaxial with the stem and'ha'vingan annular wall radiallyjspaced, for a portion of its'return length, from the body, and a bellcrank lever near the outer end of the "hood laterally oil'set therefrom,'said bell automatic release of the latch presenting an 4;. mechanism of the character indicated, a bonnet having a longitudinally bored body, a valve stem housed therein, a valve on the inner end of the stem and an inwardly directed annular hood carried at its outer end on the outer end of the stem substantial-' 1y axial with the stem and radially spaced for a portion of its return length from the body, a bracket extension. from the bonnet laterally offset from the body and a bell crank lever extension near the outer end of the hood laterally offset therefrom, said bell crank including an inwardly extending arm, a projection thereon to latch in front of the inner edge of the hood and a second arm for automatic release of the latch presenting an engagement surface to a release member in line with the extended axis of the stem.

5. In an automatic valve shut-0E mecha- 'nism including a valve unit having an axis -a-valvestem housed therein, a valve having a pivot support from'the pressed: longitudinally inwardly by a release crankincluding an inwardly extending arm, a 'projectionthereon to latch in front of the inneredge of the hood'and a second armfor "engagement surfaceto arelease member n linewith' the 'extendedaxis'of the'stem.

ment in an outward open valve position, a a

bell crank release latch pivoted near the outer end of the unit at a point laterally offset therefrom and having an inwardly extending arm latching with the unit and a release arm beyond the outer end of the unit adapted to be engaged and inwardly deflected in] line with the extended axis of the unit torej 

